Question:
How does layout system on 1.5 work?
Can I show modules on all page like previous Opencart 1.4.x?
Or set spesific Banner Module to spesific Category Page?

Answer:
With curent Layout System you can:

Set module to show on all page.

Set different module to show on different page (based on route).

Set different module (may be Banner) to different Category, Product and Information page.

If you have multi-store, you can set all feature above for different store.

Tutorial bellow will help you to understand the Layout System.

Overview: How it work?

First, opencart will check is there any Layout spesifically for Category, Product or Information Page. Then Apply it.

When first check above return false, opencart will check is there Layout based on route url is available.

When second check above return false, opencart use Store Layout as a "fallback".

Step-by-step Learn
Test this step on your demo site/ not a Live site. In this step-learn, every tutorial is an example of layout override for the step before it. So the end result is continuity from the first step.

Delete default Layout demo

System -> Design -> Layouts : delete all except DefaultWhen you force to delete a Layout that belong to store (used as base layout) you will get a message: Warning: This layout cannot be deleted as it is currently assigned as the default store layout!.

Extensions -> Modules : uninstall all

Store Layout

System -> Design -> Layouts ( Layout Pages )

rename Default into Store Default ( To avoid miss understanding about the used of default word ).

Check your site (frontpage): all page should be 1 column with no sidebar.

Extensions -> Modules ( Modules Page )

Install Category module

Add module, use curent setting:

Layout: Store Default

Position: Column Left

Status: Enabled

Sort Order: 1

Check your site: all page should be 2 column with left sidebar ( Category module ).

Route Based Layout

Homepage

Layouts Page. Insert new layout, use curent setting:

Layout Name: Homepage

Store: default

Route: common/homeIf you check your site now, homepage will show 1 column and all other page will show 2 column.